Dynamo-electric machine.



R. B.- WILLIAMSON.

DYNAMO ELECTRIC MACHINE.

APPLICATION FILED 00T. 29, 1909.

971,868. Patented ont 4,1910.`

mor/MAX UNITED STATES PATENT OFFICE.

ROBERT IB. WILLIAMSON, OF MILWAUKEE, WISCONSIN, ASSIGNOR TOAIIIS-CHALMERS COMPANY, A CORPORATION OF NEW JERSEY.

DYNAMO-ELECTRIC MACHINE.

T0 all whom it may concern:

Be it known that I, ROBERT B. l/VILLIAM- soN, a citizen of the UnitedStates, residing at Milwaukee, in the county of Milwaukee and State ofVisconsin, have invented certain new and useful Improvements inDynamo-Electric Machines, of which the following is a full, clear, andexact specification.

This invention relates to improvements in dynamo-electric machines andparticularly to dampers or anti-hunting devices for synchronous machinesor alternating current generators, and to self-starting devices forsynchronous motors.

One of the objects of the invention is the provision of damping andcombined damping and self-starting devices which have a very higheiiiciency, are inexpensive to manufacture and to apply to the machines,and which have a construction and arrangement such that they aresecurely held against movement or vibration relative to the parts towhich they are attached.

A further object is the provision of damping and self-starting devicesso constructed that they can be applied to rotating members ofdynamo-electric machines employing the standard punchings and end platesbetween which the punchings are clamped.

My invention may be briefly summarized as consisting in certain noveldetails of construction and combinations of parts which will bedescribed in the speciiication and set forth in the appended claims.

Forv an understanding of my invention reference is had to theaccompanying sheet of drawings wherein- Figure 1 is a side view of partof a rotating field member of a dynamo-electric machine equipped with myimproved damping and self-starting devices. Fig. 2 is an enlargedsectional view through a field magnet and a portion of the spider of themachine, the section being taken substantially along the line 2 2 ofFig. 1. Fig. 8 is a section taken through one of the eld magnets, thesection being at right angles to the section of Fig. 2, a portion of thespider being shown in elevation and a portion adjacent the magnet beingbroken away.

Specication of Letters Patent.

Application filed October 29, 1909.

Patented Oct. 4, 1910.

Serial No. 525,243.

Although certain features of my invention may be applied to eitherstationary or rotatable members, I have shown my invention as applied toa rotary field member having a iield frame or spider 10 mounted upon ashaft 1l and provided with a plurality of field magnets 12 which aresecured to the rim of the spider by dovetail connections. The pole 13 ofeach lield magnet is built up of laminas which are clamped between endplates 14, and surrounding each pole is a iield coil 15 formed, in thiscase, of edgewise wound strap copper. The inner ends of the coils reston coil seats 16 which bear against the periphery of the rim of thespider and on rings 17 which are L-shaped in cross section and arebolted to the sides of the rim so as to support the overhanging portionsof the coils and to prevent displacement of the field magnets. Each poleis provided with pole tips 18 and the end plates of each pole have theusual laterally projecting flanges 19 whichtogether with the pole tipsretain the coil on the pole.

Surrounding the end of each pole is a collar 20 which is formed of goodconducting material and constitutes part of the damping and selfstartingdevices. This collar is provided with a main flat portion 21 whichsurrounds the pole and is located between the eld coil 15 and the poletips 1S on the punchings and the flanges 19 of the end plates so as tobe securely held in position. The collar is provided along oppositesides of the iield magnet and just beyond the flanges 19 of the endplates with a pair of flanges 22 which extend radially outwardsubstantially to the outer end of the pole at right-angles to theportion 21.

Extending through the outer end of the pole close to the pole face andat rightangles to the planes of the laminae and to the plane of rotationof the rotary member, are a number of bars 23 which are formed of goodconducting material and have their outer ends secured to these outwardlyprojecting flanges 22 of' the collar, the bars in this case extendingthrough openings in the flanges 22 and being secured thereto by lriveting or upsetting the ends of the bars as shown most clearly in Fig.2. As shown most clearly in Fig. 3 the bars pass through partiallyclosed slots in the laminae so that as here shown the bars are notentirely surrounded by the laminae. However, it is immaterial to thepresent invention whether the slots which receive the vbars are closedor only partially closed. Then the machine is in operation the collarsand bars which extend through the poles and are secured to the collarsform seats for induced currents and prevent, in a great measure,irregularities in speed above or below synchronism in a well knownmanner. The dampers, as above described, may be employed for the purposeof making a synchronous motor self'- starting. However, when such astructure is applied to a synchronous motor, I prefer to employ incombination therewith, features which render the self-starting actionmore effective. By referring` particularly to Fig. 2 it will be seenthat the collar 2O which surrounds each pole is provided on oppositesides of the field magnet with portions 24 extending outward orlaterally beyond the coil surrounding the Dole, and at the outerextremities of these portions 24 are flanges 25 which extend radiallyinward for a short distance along opposite sides of the coil, theportions 2l, 22, 24 and 25 all being cast in one integral piece. Theseflanges 25 are, as shown clearly in Figs. 1 and 2, connected together byshort-circuiting rings 2G of conducting material, the rings being inthis case secured to the flanges by bolts 27. These rings 26 togetherwith the structure previously described constitute a closed secondary inwhich the currents may be induced as in the secondary of an inductionmotor.

It will be seen that the particular construction of the damper andself-starting structure is such that standard punchings and end platescan be employed, thus doing away with the necessity for special dies,patterns, etc., and permitting the use of a field magnet constructionwhich is absolutely safe and reliable at any speed under which themachine may be operated, the only change required in the punchings andend plates being the addition of the openings for the bars 23 and theseopenings can be very easily provided. Not only does this particularconstruction permit the use of the standard parts of the pole, but thedevice can be very easily applied to a machine and securely held inposition due to the location of the collars between the coils and thepole tips and flanges of the pole.

l do not desire to be conned to the exact details shown but aim in myclaims to cover all modifications which do not involve a departure fromthe spirit and scope of my invention.

That l claim as new and desire to secure by Letters Patent is:

l. In a dynamo-electric machine, a field pole consisting of laminae andflanged end plates between which the laminas are clamped, a coil mountedon the pole, a damping device for the pole comprising a collar having aportion surrounding the pole and located between the coil and theflanges of the end plates, a pair of flanges extending radially outwardfrom the collar along the anges of the end plates, and a plurality ofbars extending through the pole and secured to said flanges of thecollar.

2. In a dynamo-electric machine, a field magnet comprising a pole formedof laminae and end plates between which the laminae are clamped, saidlaminae and plates having coil-retaining portions extending outwardlyfrom the four sides of the pole, a coil mounted on the pole, a dampingdevice for the magnet comprising a collar having a portion surroundingthe pole and located between the coil and the coil-retaining portions ofthe pole, a pair of flanges extending radially outward from said portionof the collar and located beyond the coil-retaining portions of the endplates, and damping bars extending through the pole and secured to saidoutwardly extending fianges.

3. In a4 dynamo-electric machine, a plurality of iield magnets, eachcomprising a pole having coil-retaining portions at its outer end, and acoil surrounding the pole, a collar at the outer end of each fieldmagnet and comprising a portion located between the coil and thecoil-retaining portions of the pole, each collar having ianges extendingradially inward along opposite sides of the field magnet, andshort-circuiting rings secured to said flanges.

t. In a dynamo-electric machine, a frame or spider, a plurality of fieldmagnets secured thereto, each field magnet comprising a pole havingcoil-retaining portions at its outer end, and a coil mounted on thepole, collars surrounding the outer ends of the poles and each havingfianges extending radially outward and flanges extending radially inwardalong opposite sides of the corresponding magnet, damping bars extendingthrough the poles and secured to the outwardly extending flanges, and apair of short-circuiting rings secured to the inwardly extendingflanges.

5. A rotary field member for a dynamoelectric machine comprising a frameor spider, field magnets secured to said spider and each having a poleformed of punchings and end plates, the latter having laterallyprojecting coil-retaining portions, a coil mounted on each pole, acollar surrounding the outer end of each pole and having flangesextending radially outward along the coilretaining portions of the endplates and In testimony whereof I affix my signature, flanges extendingradially inward along opin the presence of two witnesses. 10 positesides of the Coil, damping bars extend- Milwaukee, lVis.9 Oct. 13, 1909.

ing through each pole and secured to the 7 outwardly!D extending flangesof tlie corre- ROBERT B' W ILLIAMSON spending collar, and a. pair ofsliort-eirouitlVitnesses:

ing rings secured to the inwardly extending CHAS. L. BYRON,

anges or the collars. ROB. E. STALL.

